HAVING Parkinson's disease is tough, but it was made extra difficult for Michael J. Fox recently.
The actor has lived with the condition since 1991. However, he was accused of exaggerating his symptoms on TV by talk-show host Rush Limbaugh.
Fox, 45, had filmed an ad for candidates who support stem-cell research, ahead of the Nov 7 Congressional polls in the United States.
In the interview, he was shaking so badly that, at one point, the microphone clipped to his jacket got dislodged.
Limbaugh called Fox 'really shameless' in his effort to stir up sympathy, but later apologised. Medical experts in the US also dismissed Limbaugh's claims.
In fact, Fox's symptoms are commonly experienced by many patients with Parkinson's, especially those who have been suffering from it for a long time, doctors say.
In Singapore, about 0.3 per cent of people over 50 suffer from the neurological disorder which has no known prevention or cure. About 10 per cent of the cases are hereditary.
Sufferers experience uncontrollable shaking, stiffness in the limbs, poor balance and slowness of movement.
Parkinson's occurs when nerve cells producing dopamine in the brain degenerate faster than normal for one's age.
Dopamine is responsible for transmitting motor signals. Its loss causes a person to be unable to move or control his movements.
The common drug of choice to treat this is levodopa, which replaces the lost dopamine in the brain. But it comes with side-effects. The receptors in the brain become highly sensitive to the drug over time, causing involuntary and excessive movement (dyskinesia) - something Fox put down to 'over-medication'.
As the condition progresses, the body reacts to medication unpredictably. 'It's not like taking two Panadol tablets every time you have a fever,' says Dr Tan Eng King, a senior consultant neurologist at the National Neuroscience Institute.
'It's a process that needs to be monitored closely, especially for those in the advanced stages,' he adds.
About one in three patients will develop this problem after taking the drug for more than five years, although the side-effects can be minimised with dosage adjustment or by adding other medication, says Dr Ho King Hee, a visiting consultant neurologist at Raffles Hospital.
Fox's symptoms also cannot be caused by his being 'off his medication', as Limbaugh contended, as the condition causes less movement - not more, adds Dr Ho.
In fact, the actor said he was constantly medicated. Responding to Limbaugh's remarks, he said: 'If I didn't take medication, I wouldn't be able to speak. I'd have a mask face.'
The condition is not life-threatening, but if it is not controlled well, patients may get increasingly immobile and eventually be bedridden and die from complications, says Dr Ho.
It is, however, possible to live with it for many years - especially if it's detected early.
Fox himself has lived with it for 15 years now, and is currently championing stem-cell research as a potential cure for the condition.
Early warning signs
PARKINSON'S disease, which usually afflicts people over the age of 50, can be managed more easily with early detection.
The following are some early signs of the disease that you can watch out for, either in yourself or those you care about.
Stiffness and shaking, which usually starts on one side of the body
A rigid, 'mask-like' expression on a person's face
Reduced blinking
Difficulty in writing or smaller handwriting
If you observe these symptoms, consult a doctor for advice.
Information provided by Dr Ho King Hee, a visiting consultant neurologist at Raffles Hospital